1 files changed, 39 insertions, 0 deletions
diff --git a/tests/ui/resolve/generic-params-from-outer-item-in-const-item.rs b/tests/ui/resolve/generic-params-from-outer-item-in-const-item.rs
new file mode 100644
index 000000000..e5647d72c
--- /dev/null
+++ b/tests/ui/resolve/generic-params-from-outer-item-in-const-item.rs
@@ -0,0 +1,39 @@
+// Regression test for issue #115720.
+// If a const item contains generic params from an outer items, only suggest
+// turning the const item generic if the feature `generic_const_items` is enabled.
+
+// revisions: default generic_const_items
+
+#![cfg_attr(generic_const_items, feature(generic_const_items))]
+#![feature(generic_const_exprs)] // only used for the test case "outer struct"
+#![allow(incomplete_features)]
+
+fn outer<T: Tr>() { // outer function
+    const K: u32 = T::C;
+    //~^ ERROR can't use generic parameters from outer item
+    //[generic_const_items]~| HELP try introducing a local generic parameter here
+}
+
+impl<T> Tr for T { // outer impl block
+    const C: u32 = {
+        const I: u32 = T::C;
+        //~^ ERROR can't use generic parameters from outer item
+        //[generic_const_items]~| HELP try introducing a local generic parameter here
+        I
+    };
+}
+
+struct S<T: Tr>(U32<{ // outer struct
+    const _: u32 = T::C;
+    //~^ ERROR can't use generic parameters from outer item
+    //[generic_const_items]~| HELP try introducing a local generic parameter here
+    0
+}>);
+
+trait Tr {
+    const C: u32;
+}
+
+struct U32<const N: u32>;
+
+fn main() {}